Ottawa (AP) - Top diplomats from the world's leading economies are ramping up pressure on Iran to prove its nuclear ambitions are peaceful, renewing calls for the country to be hit with new international sanctions if it fails to comply.

In meetings outside the Canadian capital on Tuesday, U.S. Secretary of State Hillary Rodham Clinton and her fellow foreign ministers from the Group of Eight main industrialized nations will warn Iran again it faces fresh penalties if it doesn't come clean on its nuclear program.

But with Iran refusing to comply, their message will be largely directed at a country not represented at the talks here: China, a permanent member of the U.N. Security Council that is not a member of the exclusive G-8 club.

Support from China, a vocal opponent of sanctions, is critical as it wields veto power on the council. Until recently, it had balked at the mere suggestion of taking additional punitive steps against Iran. That, Clinton suggested, may now be changing.

In an interview with Canadian television on Monday, Clinton said China shared the view of the U.S., its European allies and Russia that "a nuclear-armed Iran is not acceptable."

"I think as the weeks go forward and we begin the hard work of trying to come up with a Security Council resolution, China will be involved, they will be making their suggestions," she said.

Iran is already under three sets of U.N. Security Council sanctions and China had been holding up consideration of a fourth, saying diplomacy must be given more time. But last week it softened its position in a conference call among senior officials from the six nations working most closely on the matter, according to diplomats.

A senior U.S. official told reporters traveling with Clinton that the Chinese "have said now that they will engage on the elements of a sanctions resolution." The official spoke on condition of anonymity to discuss an ongoing diplomatic negotiation.

In Washington, meanwhile, President Barack Obama met Monday with China's incoming ambassador to the United States. The White House said Obama stressed to the envoy the need for the two countries "to work together and with the international community on critical global issues, including nonproliferation and pursuing sustained and balanced global growth."

Clinton and other Obama administration officials have said they want the new sanctions to target Iranian companies and government elements, like the country's Revolutionary Guard Corps, and not the Iranian people. U.S. diplomats and their colleagues have been discussing various options for months, but until now China had stayed out of the conversation.

Clinton did not address the specifics of any contribution that China might make but said she believed an agreement on new sanctions could be reached in the council. Russia, another veto-wielding member generally opposed to sanctions, has said it is open to fresh penalties.

"As in any effort, we're going to have to try to come to some consensus and we're in the middle of that process," Clinton said after answering flatly "no" when asked if the world would have to start living with a nuclear-armed Iran.

Iran insists its nuclear program is for peaceful means only. But Western powers believe the country is working to produce a nuclear weapon, as Iranian officials have refused demands to come clean about their intentions.

Iran will be the major topic of conversation at the G-8 meetings in Canada, involving Clinton and the foreign ministers of Britain, Canada, France, Germany, Italy, Japan and Russia.

They will also look at nuclear arms control in general ahead of a summit of world leaders to be hosted next month by Obama in Washington.

But the ministers will also tackle topics such as terrorism in the Sahel region of North Africa, as well as Somalia and Yemen. On Monday they announced a plan to boost trade between Afghanistan and Pakistan.

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